Welding of high strength and low weight materials like Aluminium Alloys without any defects by conventional
welding techniques is a major challenge in industries. Hence research on solid state welding techniques like Friction
stir welding and Friction welding techniques have got much importance in joining of Aluminium alloys. However
most of the industries are not changing conventional techniques as skilled workers are available on that area. Most
common conventional welding techniques used for joining of Aluminium alloys are Gas welding and Arc welding.
Friction welding is a solid-state welding process that generates heat through mechanical friction between a moving
and a stationary component with the addition of a lateral force called “upset” to plast ically displace and fuse the
materials. In this work, experimental study on tensile and micro structural characteristics of welded joints formed
from conventional welding techniques and Rotary friction welding(suitable for weld specimens with circular cross
section) has been carried out and the same were compared. The process parameters for arc welding used was 50-70
Amp reverse polarity DC and electrodes of 2.3mm diameter. In Gas welding, the parameters were oxy acetylene
neural flame at 3200°C and 3mm electrodes . In the case of friction welding an axial pressure loading of 3Mpa with
5 MPa as upsetting pressure and 500 rpm were used to obtain good welded joints. Tensile characteristic studies of
Arc welded joints and Gas welded joints showed 48% and 60 % variations respectively from the maximum load
bearing characteristics of parent metal. In the case of friction welded joint, the variation was found to 46%. Micro
structural evaluation of conventionally welded joints exhibited clear distinct zones of various weld regions. In the
case of friction welded joint micro structural photographs showed comparable features both in parent metal and
welded region. Thus the tensile characteristic study and microstructure evaluations proved that friction welded joints
are good in both aspects compared to conventionally welded joints.

Description:

International Journal of Innovative Research in Science, Engineering and Technology,Volume 2, Special Issue 1, December 2013

Bank switching in embedded processors having partitioned memory architecture results in code size as well as run time overhead. An algorithm and its application to assist the compiler in eliminating the redundant bank switching codes introduced and deciding the optimum data allocation to banked memory is presented in this work. A relation matrix formed for the memory bank state transition corresponding to each bank selection instruction is used for the detection of redundant codes. Data allocation to memory is done by considering all possible permutation of memory banks and combination of data. The compiler output corresponding to each data mapping scheme is subjected to a static machine code analysis which identifies the one with minimum number of bank switching codes. Even though the method is compiler independent, the algorithm utilizes certain architectural features of the target processor. A prototype based on PIC 16F87X microcontrollers is described. This method scales well into larger number of memory blocks and other architectures so that high performance compilers can integrate this technique for efficient code generation. The technique is illustrated with an example

Corrosion characteristics of brass panels were investigated
in the Vembanad estuarine water (Cochin Harbor), India over a
period of one year. The corrosion rate of brass samples during
exposure was determined by gravimetric method and fouling
on panels was assessed, exposure-wise, in terms of biomass.
Corrosion products were identified by X-Ray diffraction. The
results of the study were discussed in the light of the seawater
characteristics

Corrosion represents one of the largest through
life cost component of ships. Ship owners and operators
recognize that combating corrosion significantly impacts the
vessels’ reliability, availability and through life costs. Primary
objective of this paper is to review various inspections,
monitoring systems and life cycle management with respect to
corrosion control of ships and to develop the concept of
“Corrosion Health” (CH) which would quantify the extent of
corrosion at any point of ships’ operational life. A system
approach in which the ship structure is considered as a
corrosion system and divided into several corrosion zones, with
distinct characteristics, is presented. Various corrosion
assessment criteria for assessment of corrosion condition are
listed. A CH rating system for representation of complex
corrosion condition with a numeric number along with
recommendations for repair/maintenance action is also
discussed

Description:

International Journal of Environmental Science and Development, Vol. 5, No. 5, October 2014

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In order to minimize the risk of failures or major
renewals of hull structures during the ship's expected life span,
it is imperative that the precaution must be taken with regard to
an adequate margin of safety against any one or combination of
failure modes including excessive yielding, buckling, brittle
fracture, fatigue and corrosion. The most efficient system for
combating underwater corrosion is 'cathodic protection'. The
basic principle of this method is that the ship's structure is made
cathodic, i.e. the anodic (corrosion) reactions are suppressed by
the application of an opposing current and the ship is there by
protected. This paper deals with state of art in cathodic
protection and its programming in ship structure

Description:

International Journal of Chemical Engineering and Applications, Vol. 1, No. 3, October 2010

Inhibited α brasses are largely immune to
dezincification in most water, but the effect of tin and arsenic
addition to α/β brasses is not so reliable or predictable in
controlling the problem. There have been many cases of
dezincification in duplex brasses in both fresh water and
seawater. There is no reliable method of inhibiting the
dezincification of two-phase brass despite there are some
protection methods such as inhibitors, electro deposition and
electro polymerization. Organic coatings are effectively used for
the protection of metals due to their capacity to act as a physical
barrier between the metal surface and corrosive environment.
Hence, epoxy coating on brass was applied and effect of this
against dezincification in Cochin estuarine water over a period
of one year was studied and reported in this paper

Description:

International Journal of Chemical Engineering and Applications, Vol. 1, No. 2, August 2010

Friction welding is a solid state joining process that produces coalescence in materials, using the
heat developed between surfaces through a combination of mechanical induced rubbing motion and
applied load. In rotary friction welding technique heat is generated by the conversion of mechanical
energy into thermal energy at the interface of the work pieces during rotation under pressure.
Traditionally friction welding is carried out on a dedicated machine because of its adaptability to mass
production. In the present work, steps were made to modify a conventional lathe to rotary friction welding
set up to obtain friction welding with different interface surface geometries at two different speeds and to
carry out tensile characteristic studies. The surface geometries welded include flat-flat, flat-tapered,
tapered-tapered, concave-convex and convex-convex. A comparison of maximum load, breaking load and
percentage elongation of different welded geometries has been realized through this project. The
maximum load and breaking load were found to be highest for weld formed between rotating flat and
stationary tapered at 500RPM and the values were 19.219kN and 14.28 kN respectively. The percentage
elongation was found to be highest for weld formed between rotating flat and stationary flat at 500RPM
and the value was 21.4%. Hence from the studies it is cleared that process parameter like “interfacing
surface geometries” of weld specimens have strong influence on tensile characteristics of friction welded
joints

Description:

International Journal of Innovative Research in Science, Engineering and Technology,Volume 2, Special Issue 1, December 2013

A sandwich construction is a special form of the laminated composite consisting of light weight core, sandwiched between two stiff thin
face sheets. Due to high stiffness to weight ratio, sandwich construction is widely adopted in aerospace industries. As a process dependent bonded
structure, the most severe defects associated with sandwich construction are debond (skin core bond failure) and dent (locally deformed skin
associated with core crushing). Reasons for debond may be attributed to initial manufacturing flaws or in service loads and dent can be caused by
tool drops or impacts by foreign objects. This paper presents an evaluation on the performance of honeycomb sandwich cantilever beam with the
presence of debond or dent, using layered finite element models. Dent is idealized by accounting core crushing in the core thickness along with the
eccentricity of the skin. Debond is idealized using multilaminate modeling at debond location with contact element between the laminates.
Vibration and buckling behavior of metallic honeycomb sandwich beam with and without damage are carried out. Buckling load factor, natural
frequency, mode shape and modal strain energy are evaluated using finite element package ANSYS 13.0. Study shows that debond affect the
performance of the structure more severely than dent. Reduction in the fundamental frequencies due to the presence of dent or debond is not
significant for the case considered. But the debond reduces the buckling load factor significantly. Dent of size 8-20% of core thickness shows 13%
reduction in buckling load capacity of the sandwich column. But debond of the same size reduced the buckling load capacity by about 90%. This
underscores the importance of detecting these damages in the initiation level itself to avoid catastrophic failures. Influence of the damages on
fundamental frequencies, mode shape and modal strain energy are examined. Effectiveness of these parameters as a damage detection tool for
sandwich structure is also assessed

Soils are multiphase materials comprised of mineral grains, air voids and water. Soils are not linearly elastic
or perfectly plastic for external loading. Various constitutive models are available to describe the various aspects of soil
behaviour. But no single soil model can completely describe the behaviour of real soil under all conditions. This paper
attempts to compare various soil models and suggest a suitable model for the Soil Structure Interaction analysis especially
for Kochi marine clay.

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The paper identifies twelve elements of ship recycling and highlights their respective roles and duties in a proposed ship
recycling system. The source and items of knowledgebase for ship recycling have been brought out. A new philosophy focusing clean
and safe ship recycling namely design for ship recycling has been introduced based on principles such as ecofriendliness, engineering
efficiency, energy conservation and ergonomics. The role of naval architects in ship recycling industry has been described based on the
above factors. The paper brings out the role of naval architects in ship recycling the way it has been practiced worldwide and proposed
by regulatory bodies. The authors have brought out the new concept of design for ship recycling and various aspects of it. The role of
naval architects in the practice of this new design philosophy which is ready to be embraced by the maritime industry has been
reiterated.